Reinforced rubber tubes



I United States Patent [1113,536,104

[72] Inventor Danielldeune 3,318,337 5/1967 Bauer 138/130 CmFemnd FrancePrimary Examinerl.averne D. Geiger PP 699,254 Assistant Examiner-R. J.Sher f' ted a? Atz0rneyBrunbaugh, Graves, Donohue & Raymond a en [73]Assignee Compegnle Genet-ale Des Michell", ABSTRACT: A rubber tube isprovided with concentric layers clemt'hmndmuy'de'nom) France ,of meta]cables. The cables in successive layers are wound Pnomy 1967helicoidally alternatingly in the S direction and the Z direction [33] Maround the axis of the tube. Each cable comprises a plurality [31] 1871of concentric layers of elemental wires all wound helicoidally in thesame direction around the axis of the cable. The direction of winding ofthe elemental wires around the axis of [54] 22 i TUBES each cable is thesame as the direction of winding around the axis of the tube of suchcable. [52] US. Cl 138/ 130, In placing a metal armor, including aplurality f cables, on 138/138 a tube, the cables, are woundhelicoidally on the tube and [51] Int. Cl F16! 11/08 t i t d b t th i ia number f turns per meter b m [50] Field ofSearch 138/138, any equal to500 Sin zaJflD whemin D is the diameter in 130, 137, 132, 133 limetersof the helix formed by the wound cable and a is the angle formed by thewound cable with the axis of the helix, the [56] Rekm cued H 1 directionof the twisting being opposite to the direction of the UNITED STATESPATENTS winding twist imparted to the cables about their axes by virtue1,011,090 12/191 1 Subers 138/130 of their being wound helicoidally,whereby the winding twist is 2,151,307 3/1939 Smith 138/138 1compensated at least partially.

Patented o'cnz'z, 1970 3,536,104

FIG. 4

IN VEN TOR.

DANIEL LEJEUNE .15 6mm A his ATTORNEYS REINFORCED RUBBER TunisBACKGROUND OF THE INVENTION This invention relates to improvements ofreinforced rubber tubes and, more particularly, to tubes thereinforcement of which comprises metal cords arranged in concentricsuperimposed layers rather than in braids. The invention relates also toa novel and highly effective method of placement of a metal armor,including a plurality of cables, on a tube.

The 'armoring of rubber tubing by means of wires orcables is well known.The wires or cables may consist of textiles or metals in plies and notbraided; i.e., the textiles or metals may be arranged in superimposedlayers which are concentric and wound helicoidally around the axis ofthe tube, the direction of the winding alternating from layer to layer.By means of an armor in plies, one obtains a more elastic tubing than bymeans of a braided armor, while the resistance is at least comparable ifone uses wires or cables which adhere well to the elastomer employed inthe tube.

In order to provide rubber tubing with very high resistance,

especially to internal pressure, it is of course advisable to use ametal reinforcement comprising cables fonned by assembling elementalwires of small diameter, for example, ranging from 0.10 to 0.25 mm, sothat the elasticity of the armored tube is preserved. Towards such end,it is customary to use cables wherein the elemental wires are assembledin strands which, in turn, are assembled with one another in order toform a cable.

In place of stranded cables, which have the disadvantage of having anoverall cross section which is comparatively large in I relation to thetotal cross section of the elemental metal wires SUMMARY OF THEINVENTION An object of the present invention is to remedy thedisadvantage noted above of tubes reinforced by cables comprising wiresdistributed in layers. A further object of the invention is to obtain,for the same overall dimension of the reinforcement, more resistanttubes than conventional tubes having cables composed of strands. Anotherobject of the invention is to provide tubes of the expansible kindsuitable for purposes of hydraulic rock blasting or for piping in waterunder pressure, especially into coal or ore in massive deposits.

The foregoing and other objects of the invention are attained by theprovision of rubber tubes with metal armor, the tubes comprising an evennumber of layers of cables wound altematingly in S- and in Z-form aroundthe axis of the tube. The tubes are characterized in that each cablethereof is composed of several superimposed and concentric layers ofelemental wires, preferably all wound helicoidally in the same direction(S or Z), while it is furthermore preferred that the direction of the Sor Z windings of these elemental wires be the same as the direction ofhelicoidal winding around the axis of the tube of the cable to which thewindings pertain.

The two forms, S and Z, of helicoidal winding of a cable around an axisare easy to distinguish by imagining that the cable segments on the sideof the axis towards the observer are the central portions of one ofthose two letters. The type of winding as established by this testremains the same regardless of the direction from which the cable isviewed and regardless of the orientation of the cable.

The method in accordance with the invention of applying the sheathing ofa tube comprises compensating in part or in full for the twist impartedto the cables during their helicoidal winding, by means of anuntwisting, either in advance, which 500 sin 2a 'rrD the diameter inmillimeters of the helix formed by the wound cable and a is the angleformed by the wound cable with the preferably wherein D is axis of thehelix.

A single wire which is helically wound around a cylinder undergoes, as aresult of such winding, a twist the direction of which depends on thedirection of winding around the cylinder and the amplitude of which isthe product of (a) the number of helical turns and (b) cosa.

In a cable which consists of several layers of single or elementalwires, one creates a twist upon winding the cable helicoidally unlessone takes compensating precautions. Such twist results in thedisplacement of the wires of the various layers with respect to oneanother. This disadvantage becomes more serious if the wires of thevarious layers are wound helicoidally in different directions, forexample altematingly in S or in Z form, and also if the direction of theS- or Z-winding of the-cable differs from the direction of winding ofthe element'al wires, mainly of the outermost layer. Even if oneprovides for compensation of the twist resulting from the helicoidalwinding, it is important that one use as cables wound in S formationsuch cables as have all their wires likewise wound in S formation, andas cables wound in Z formation such cables as have all their wireslikewise wound in Z formation. By virtue of this construction, avariation of the diameter of the tube or a variation of the angle ofinclination of the cables, due to any stresses to which the tube may besubjected during service, causes all the cables and all the elementalwires to respond in the same manner and in the same direction. Thestresses are thus more uniformly distributed, and the cables or wireswound in one direction are not overstressed in relation to the cables orwires wound in the other direction.

As concerns the method of application or laying in accordance with theinvention, the twist engendered on helicoidal winding may be compensatedeither when the cables are laid or before that.

For the purpose of compensation of the twist during the application, itis sufl'rcient to provide for turning feed reels. The cable reels, whileunrolling, must simultaneously be driven in rotation around an axisperpendicular to their longitudinal axis, so as to impart to the cablewhich is being helicoidally wound around the tube being fabricated atwist which is opposite that which it undergoes by virtue of thehelicoidal winding. The speed of twisting or of untwisting should yielda number of turns per meter of cable which is approximately 45 plus orminus approximately 10 to 15 and consequently sin 20: is always close to1, this term may generally be simplified to l60/D, D being the diameterin millimeter of the helix formed by the'wound cable.

If no turning reels are available, the twist may be compensated inadvance by giving the cable a suitable kinking or twist. The cableshould be in equilibrium, i.e., it should become inert, after beingwound at a given angle to form a helix of given diameter. For example,for a helicoidal winding with a diameter of 16mm at an angle of 54, thecable should have a tendency to kink or twist 9 to 10 turns per meter,regardless of whether wound in S or Z formation. This tendency to kinkis imparted during manufacture of the cable by giving the core of thecable as well as the wires constituting the outer layer or layers somepre-twistings in the suitable direction, prior to assembly. Thissolution is economically preferable inasmuch as it simplifies theequipment needed for placing of the armor of the tube without therebycomplicating the manufacture of the cables beyond the capabilites of theequipment customarily used.

' wherein:

3 BRIEF DESCRIPTION or me DRAWING Additional aspects of the inventionmaybe understood by] i t a reference to the following detaileddescription of a representa-x a tive embodiment thereof and 1 ton theattached drawings, a

FIG. 1 is across cordance with the invention; 7 FIG. 12 isa brokenaawayview in e FlGllp" FIG; 3 is a crosss ection of a tubein accordance withtheinvention having two layers of cables of the type shown in FIGS.

hsscm h OF THE PREFERRED EMBODIMENT e In no. 1, thereappears the cable10 containing three conlclaim:

centric layersll, 12 and l3of elemental wireszl4. These layers comprise,respectively,;three, nine and fifteen steel wires of 0.18 mmdiameter.All wires are woundhelicoidallyv aroundthe axis l5.of the cable.

As shown in FlG. 2; the wires of the erent layers areall o wound in thesame direction, i.e.,:in Z directionin this FIG;

The windingdirection is the same if FIG. 2 is viewed upside:

down, for example. The pitches :of the different layers 16;! mm for theinterior layer ll, 12 mm for the intermediate layer 1 l2 and 6 rnmforthe outer layer 13.

FIG. 3 shows in cross section a tube 20in accordance with t of-a cablewith three layersof w wires and adapted tofacilitate formation ofa tubein 36 3f levation of g the cable of i 0 a broken-away prospective viewof the tube of FIG.

the inventionilhere are in succession; from the inside towards theoutside an inner lining 21; two layers 22 23hr cables 24 and 25 embeddedin an elastomer 26,and an outer protect tive sheath 27. As seen in no.4. the two cables 24m: 25 are 3 1 of the type shown in nosgi and 2butdifl'er in their direction 1 1 of. winding around the axis 28 of tubewith the direction of winding of the elemental I'wires forming them. Thecabl'e24f" is w ou nd in S direction and comprises wires which are 40wound in S direction. The cable 25 is wound-in Z direction; a x andconsists of wires likewise wound in Z direction. The cables 24 and 25form anangle a of40? with the axisu and describe are; given anuntwisting of approximatelyfive turns per meter to compensate for thetwist caused by the helicoidal 7 The tube shown in H6; 3 is anexpansible tube used for helices having an average diameter of 28 mm'.Thus, the cablesi 4 "hydraulic blasti bars.

Thus there of which the tubecan be manufac tion at minimum cost. 1

Many modifications inform and thereof within the scope of the claims.

I. A rubber tube comp direction aroundthe axis of thecable,ithedirecti0nof winding of the eleinent alwires around the axis ofeach cable being the same as the direction of winding around the axis ofthe tube of such cable andthe pitches of thelwindings of the e 30 wiresin successive layersbeing different.i

2. In a method of placement ot: a metal armor, including a g pluralityof cables, on a tube, the steps comprising winding the tcableshelicoidally on the tube and twistingthe cables about 1 their axesa number of turns per meter substantially equal to Is00tin2a"' V 1 '1rDT I e i millimeters of the helix formed by the wou nd cable, and a isthe anglevformed by the wound cable with the axis of the helix, thedirection of the twisting being opposite to the direction of r ,thewinding twist imparted to thecables about their axes by virtue of theirbeing wound helicoidally, whereby said winding twist is compensated atleast partially; V

, 3. The method of claim 2 in which said twisting preceds said 4. Themethod ofclaim2 in whi are simultaneous.

ng of rocks; it resists a working pressure of 600 detail of therepresentative, embodiment of the invention disclosed herein willreadily occur xtorthoseskilled in For example while a tube. having onlytwo layers of cables is illustrated, one having four or morelayers mayalso be employed; Accordingly, the invena tion isto beconstruedasincluding allthe modifications g even'number of concentric: 1 layersof metal cables; the cablesin successive layers being wound helicoidallyaltematingly in opposite directions around the axis'of the tube; eachcable comprising a plurality of concentric layers of elemental'wires allwound helicoidally in the wwherein D is diameter in e saidltwisting andwinding in

